Состояние ценопопуляций бобовых (Fabaceae) на степных пастбищах Республики Алтай

Abstract

The influence of grazing on the species of the Fabaceae family in the steppe communities of the Altai Republic was studied. It was found that on the steppe pastures of the middle mountains, there is a wide manifestation of signs of pasture digression, which mainly indicate the presence of intensive grazing of farm animals. The participation of leguminous plants in living aboveground phytomass in emerging transitional communities ranges from 25–50% in meadow steppes to 5–28% in real ones and up to 11–17% in desertified cenoses, which is largely determined by the peculiarities of their adaptation to pasture load and to natural and climatic factors. Under the influence of intensive grazing on the steppe pastures of the Altai Republic, accelerated aging and a decrease in the productivity of the aboveground mass are observed in most legume species. Enhanced grazing negatively affects both the morphometric parameters of all studied species and the ontogenetic structure of their coenopopulations. The degree of resistance to anthropogenic impact of each species is largely determined by its belonging to a particular life form and its lability. The least resistant to grazing and mowing were long-shoot caudex perennials, which are found only in the initial stages of herbage suppression, since with regular alienation of shoots they do not form seeds and quickly fall out of the herbage. Rhizomatous (Medicago falcata, Astragalus tibetanus) species can be kept in communities in the absence of seed renewal. Semi-rosette (Astragalus austrosibiricus, Hedysarum gmelinii) and rosette (Astragalus laguroides, A. testiculatus, A. dilutus, Gueldenstaedtia monophylla, Oxytropis pumila) tap-rooted perennials are capable of restoring cenopopulations after cessation of pasture load due to renewal buds remaining on perennial parts of the caudex. When growing conditions change (temporary cessation or reduction of pasture load, good moisture), adaptive reactions are activated aimed at the rapid growth of shoots after the removal of the negative factor.